Time for Ireland to take target with MBT

A recent report has looked at the potential of MBT to help meet landfill targets in a country where opposition to incineration still runs high

Can mechanical biological treatment (MBT) help Ireland meet it waste targets? Incineration as a technology choice remains a contentious one in Ireland - with this in mind, a report has examined the potential of MBT as an alternative solution to tackle the country's residual waste problem.

The report, Meeting Ireland's waste targets: The role of MBT, was commissioned by Greenstar and carried out by Eunomia Research & Consulting. It set out to shed some light on the following: what MBT-type activity is currently occurring in Ireland; which policies support (or could be adapted to support) MBT; what might be done to foster its development; and how its deployment would affect Ireland's ability to meet its waste management targets and objectives.

In terms of existing activity, the report found there were waste management operations - sometimes spread over two different sites - which might broadly be considered as MBT. However, in some cases, the biological part of the treatment was either not in place, or not well developed. Materials from these operations tend to be consigned to landfill and relatively little is known about the level of stability achieved through any of the biological treatments used.

The study also found there was no real incentive for operators to invest heavily in biological treatment, due to the decline in landfill gate fees and a lack of government regulation outlining how the stabilisation of waste might be used to help reduce the biodegradability of material landfilled. To address this, the report called for greater incentives and regulatory changes. Firstly, that the Government should re-design the existing landfill levy as follows:

To increase the levy on landfilling untreated waste to 75 euro per tonne of waste landfilled in late 2009/early 2010

To introduce a levy on waste sent for incineration of 55 euro per tonne of waste in late 2009/2010

To introduce a levy on stabilised waste sent for landfill of 15 euro per tonne of waste in late 2009/early 2010

It also recommended that the Government should consider supporting investments in abatement equipment to facilitate the expansion of markets for solid recovered fuels (SRF) and refuse-derived fuels (RDF). And to refund revenues from the restructured levy to waste collectors to encourage collection systems that generate low quantities of residual waste per household.

A number of regulatory measures were also outlined. These included calling on the Environmental Protection Agency (EPA) to introduce a threshold level of stability below which waste is no longer considered biodegradable for the purposes of the Landfill Directive.

Can MBT perform where it matters?The report went on to look at whether MBT would enable Ireland to meet its waste targets. It assessed the performance of six waste management scenarios: high recycling; high incineration; widespread MBT; widespread MBT plus incineration; MBT, no incineration or C&D waste, ban on landfilling of raw municipal waste; MBT, stabilisation only, ban on landfilling of raw municipal waste.

Several key findings emerged. Firstly, that the progression towards a 70% household waste recycling rate by 2017, and a commercial recycling rate of 75% by 2013, was not sufficient to meet landfill targets. Even with high incineration, the target to reduce waste landfilled to 10% of total would not be met in any year other than 2017. If the approach was taken to widely adopt MBT, the report estimated that by 2010, some 840,000 tonnes of MBT capacity would be required.

While some existing facilities might be able to be adapted to provide some of this capacity, extra plants would need to enter the development phase almost immediately for targets to be met. The report went on to project that the MBT capacity needed in 2032 to meet all of Ireland's targets would rise to 1.3M tonnes, and said a 'front-end loaded' approach was needed to build the necessary infrastructure.

While the study concluded that "no single treatment does all things", it pointed out the importance of Ireland maintaining pressure to reduce the quantity of waste generated, and to increase recycling rates over time. As far as residual waste was concerned, it maintained that MBT can deliver much of what is required. Most pressing is the need to rapidly install more treatment capacity. With the build time for basic facilities close to one year, this leaves a very short period of time for applications to move through the planning process. According to the report, the incentive and regulatory framework needs to be developed swiftly to take account of this so that developers can start planning with confidence.

If this done, then Ireland could adapt existing facilities where the biological element of MBT is, in some cases, almost a silent one. It could also develop the necessary capacity while seeking to move forward in terms of prevention and source separation, and thus move closer to achieving its Landfill Directive targets.